The present invention relates generally to disc drive data storage systems. More particularly, the present invention relates to a slider air bearing surface design which results in improved take-off characteristics and which eliminates the need for a taper at the leading edge end of the air bearing surface.
Disc drive data storage devices are well-known in the industry. In certain types of disc drives, digital data is written to and read from a thin layer of magnetizable material on the surface of rotating discs. Write and read operations are performed through one or more transducers which are carried in a slider body. The slider and transducer(s) are sometimes collectively referred to as a head, and typically a single head is associated with each disc surface. The heads are selectively moved under the control of electronic circuitry to any one of a plurality of circular, concentric data tracks on the disc surface by an actuator device. Each slider body includes a self-acting hydrodynamic air bearing surface (ABS). As the disc rotates, the disc pulls a very thin layer of air beneath the ABS, which develops a lifting force that causes the slider to lift and "fly" several .mu.inches above the disc surface.
Stiction forces adversely affect contact start and stop (CSS) performance of the slider, and may be high enough to prevent the spindle motor from rotating the disc prior to the head slider take-off from the surface of the disc. One method of reducing the stiction and improving CSS performance is to lap a crown along the length of the ABS by pressing the slider against a spherically shaped lapping plate. A crowned ABS reduces collection of lubrication between the slider and the disc. However, more complete solutions to reducing stiction are desired.
Since the introduction of a taper at the leading edge of the ABS, head take-off has improved, thus improving CSS performance dramatically. The air flow entrapped in the taper permits the air bearing film to start forming at the leading edge of the slider. Progressively, the air bearing forms around all of the rails to encompass the trailing edge area. However, machining of the taper region is not a precise process and requires removal of a large amount of material. Tolerances on the taper region impact the fly height mean and sigma of the ABS, rendering some air bearing concepts impractical due to their sensitivity to the taper length and/or shape. The surface finish requirement of the taper region is less stringent than the remaining ABS, raising concerns about head rocking leading to taper-to-media contact during the take-off process. As the size of sliders continues to decrease in the industry, it becomes a greater challenge to control the geometrical properties (for example, taper and crown) of the slider.